really neat! it would be interesting to see a close up pic of the circuit board, so we could read the numbers on the components, and see when it was made....
On Tuesday, November 14, 2023 at 11:55:39 AM UTC-7 Magnedyne wrote: > I have opened it up and removed all of the crumbling foam it was filled > with. Lucky me, it wasn't foam which turned to goop. > Well, the tubes are not socketed, instead they're directly soldered in. So > definitely not corrosion. Seems like it's the tubes. > > [image: IMG_20231114_194941.jpg] > > Paul Andrews schrieb am Dienstag, 14. November 2023 um 16:09:22 UTC+1: > >> Regarding the yield? Just my (and others) experience with 'new old stock' >> tubes. I don't have any information on what the yield was at the time of >> manufacture. Its easy to rationalize a low yield because of the large seal >> between the glass and the body, but that would just be guesswork. >> >> Interesting that the affected tubes were better in the original photos. >> In the U.S. we have a product called 'deoxit' that is used to fix old >> electrical contacts that may have some dirt/corrosion on them. It is just >> sprayed on the contacts and then the device is used as normal, though I >> don't know what the breakdown voltage is of the product. I have used it in >> old vacuum tube devices. >> >> On Tuesday, November 14, 2023 at 12:56:18 AM UTC-5 Magnedyne wrote: >> >>> >>> Alright, thanks for the tips. I’ll see what I can do. Not doubling the >>> current on other tubes should be obvious, if anything ill modify the >>> circuit on those to run on like 60% current or something, don’t want those >>> to wear out after all. How long would I double the current on the affected >>> tubes? I’m guessing until it lights up entirely, but what if it doesn’t? I >>> don’t want to risk damaging any tubes further unless I have access to a >>> replacement. Interesting regarding the yield, where did you find that info? >>> Paul Andrews schrieb am Montag, 13. November 2023 um 22:55:13 UTC+1: >>> >>>> Because all the segments are in the same plane, it is possible that >>>> they could all get deposits equally, so increasing the current may work. >>>> Yes, the current is controlled by a resistor. The documentation I linked >>>> you to gives the recommended current for each segment. To try to >>>> re-condition the segments I would double the current, but I would only do >>>> that with the affected tubes. >>>> >>>> These tubes are known for having a low yield so it is possible that the >>>> affected tubes have other problems, such as outgassing. I would be very >>>> careful when removing them from any socket they may be in to avoid >>>> breaking >>>> a seal between the pin and the tube. >>>> >>>> On Monday, November 13, 2023 at 4:22:00 PM UTC-5 Magnedyne wrote: >>>> >>>>> >>>>> Furthermore I should mention that the partial glow does not affect >>>>> only specific elements of the tube but any element inside the tube. >>>>> Can this be caused by deposits? >>>>> Nicholas Stock schrieb am Montag, 13. November 2023 um 21:56:10 UTC+1: >>>>> >>>>>> WHAT A FIND!!! OMG. I didn't even know there were smaller versions of >>>>>> the ZM1350 (shame on me!). >>>>>> >>>>>> The tubes with the partially lit segments can probably be revived >>>>>> with a little extra current... just be careful not to burn them during >>>>>> the >>>>>> healing process (if it works..). >>>>>> >>>>>> Wow.. >>>>>> >>>>>> Welcome to the group, >>>>>> >>>>>> Nick >>>>>> >>>>>> On Mon, Nov 13, 2023 at 12:07 PM Magnedyne <miro.s...@airgrips.de> >>>>>> wrote: >>>>>> >>>>>>> Well, this serves as my introduction and and as a thread about a >>>>>>> beautiful sign I just picked up. >>>>>>> Firstly something about myself. >>>>>>> I’m a 17 year old collector and (hobby) historian of vintage >>>>>>> computers, my interests are mainly minis, mainframes, early micros and >>>>>>> kit/diy computers. But I’ve got a few other different bits and bobs >>>>>>> throughout the history of technology as well. >>>>>>> Now back to the reason I joined this group. >>>>>>> I came across an absolutely beautiful Telefunken advertising sign >>>>>>> for the, frankly underdocumented, Telefunken Varisymbol tubes. They >>>>>>> were >>>>>>> Telefunkens response to the Burroughs 7971 alphanumerical tubes. These >>>>>>> were >>>>>>> only sold for a very brief amount of time and exclusively in Europe. >>>>>>> Interestingly these are flat like panaplex tubes and the anode is >>>>>>> not a grid, but a coating on the inside of the tube. These are the >>>>>>> earliest >>>>>>> gas discharge tubes, well the ones I’m aware of anyhow, which used such >>>>>>> a >>>>>>> coating. >>>>>>> The sign is a handmade one off which was lugged around to fairs to >>>>>>> advertise the Varisymbol to potential Customers. It implements all >>>>>>> three >>>>>>> sizes of the Varisymbol ZM1350 ZM1360 & ZM1370. It can alternate >>>>>>> between >>>>>>> „TELEFUNKEN“ and „VARISYMBOL“ at four different speeds. Switching >>>>>>> between >>>>>>> the sign reading „TELEFUNKEN“ three times, then „VARISYMBOL“ three >>>>>>> times >>>>>>> and the sign reading „TELEFUNKEN VARISYMBOL TELEFUNKEN“/ „VARISYMBOL >>>>>>> TELEFUNKEN VARISYMBOL“ is possible as well. Unfortunately three tubes >>>>>>> don’t display quite properly. I’m hoping it’s just the electronics, I >>>>>>> haven’t had time for a detailed diagnosis yet. Even if it’s the tubes, >>>>>>> it >>>>>>> seems to be the most common type at least, the ZM1350 which seems to >>>>>>> have >>>>>>> popped up most often in the past. >>>>>>> Any further info about the Varisymbol is greatly appreciated. >>>>>>> Cheers, >>>>>>> Magnedyne >>>>>>> [image: IMG_0026.jpeg] >>>>>>> >>>>>>> [image: IMG_0025.jpeg] >>>>>>> [image: IMG_0021.jpeg] >>>>>>> >>>>>>> >>>>>>> >>>>>>> -- >>>>>>> You received this message because you are subscribed to the Google >>>>>>> Groups "neonixie-l" group. >>>>>>> To unsubscribe from this group and stop receiving emails from it, >>>>>>> send an email to neonixie-l+...@googlegroups.com. >>>>>>> To view this discussion on the web, visit >>>>>>> https://groups.google.com/d/msgid/neonixie-l/20e32d2c-3ac1-4656-b532-77b22f6a35f1n%40googlegroups.com >>>>>>> >>>>>>> <https://groups.google.com/d/msgid/neonixie-l/20e32d2c-3ac1-4656-b532-77b22f6a35f1n%40googlegroups.com?utm_medium=email&utm_source=footer> >>>>>>> . >>>>>>> >>>>>> -- You received this message because you are subscribed to the Google Groups "neonixie-l" group. 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